1   /**
2    * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3    *
4    * Permission is hereby granted, free of charge, to any person obtaining a copy
5    * of this software and associated documentation files (the "Software"), to deal
6    * in the Software without restriction, including without limitation the rights
7    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8    * copies of the Software, and to permit persons to whom the Software is
9    * furnished to do so, subject to the following conditions:
10   *
11   * The above copyright notice and this permission notice shall be included in
12   * all copies or substantial portions of the Software.
13   *
14   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20   * SOFTWARE.
21   */
22  
23  package com.liferay.portal.servlet;
24  
25  import java.io.Serializable;
26  
27  import java.util.Map;
28  import java.util.concurrent.ConcurrentHashMap;
29  
30  import javax.servlet.http.HttpSession;
31  
32  /**
33   * <a href="SharedSessionAttributeCache.java.html"><b><i>View Source</i></b></a>
34   *
35   * @author Michael C. Han
36   */
37  public class SharedSessionAttributeCache implements Serializable {
38  
39      public static SharedSessionAttributeCache getInstance(HttpSession session) {
40          synchronized (session) {
41              SharedSessionAttributeCache cache =
42                  (SharedSessionAttributeCache)session.getAttribute(_SESSION_KEY);
43  
44              if (cache == null) {
45                  cache = new SharedSessionAttributeCache();
46  
47                  session.setAttribute(_SESSION_KEY, cache);
48              }
49  
50              return cache;
51          }
52      }
53  
54      public boolean contains(String name) {
55          return _attributes.containsKey(name);
56      }
57  
58      public Map<String, Object> getValues() {
59          return _attributes;
60      }
61  
62      public void removeAttribute(String key) {
63          _attributes.remove(key);
64      }
65  
66      public void setAttribute(String key, Object value) {
67          _attributes.put(key, value);
68      }
69  
70      private SharedSessionAttributeCache() {
71          _attributes = new ConcurrentHashMap<String, Object>();
72      }
73  
74      private static final String _SESSION_KEY =
75          SharedSessionAttributeCache.class.getName();
76  
77      private Map<String, Object> _attributes;
78  
79  }